Self-extinguishing candle

ABSTRACT

A self-extinguishing candle is provided which, in a preferred configuration, comprises a candle having a wick with a series of alternating combustion and non-combustion zones. In use, the wick will burn through the combustion zone, and will be extinguished on reaching the non-combustion zone. The non-combustion zone is preferably provided by a physical or chemical means, and the candle can be re-lit by removal of the non-combustion means. A safer candle is provided that will self-extinguish on a regular basis.

FIELD OF THE INVENTION

The present invention relates to the field of candles, and in particular, relates to a candle which is capable of extinguishing itself automatically.

BACKGROUND OF THE INVENTION

Candles have been known for centuries and typically comprise a wick surrounded by a solid core of a combustible material which acts as a fuel. On heating by the flame of the candle, the combustible material in the area surrounding the burning wick is liquified so as to provide fluid material to the wick in order to support combustion. As the fuel is consumed, a portion of the wick is burnt so that the wick height above the candle remains relatively constant as the candle burns.

Since the use of a candle requires an open flame, safety precautions are required in order that the burning flame is monitored. However, frequently, a candle is lit and then left unsupervised for hours until the solid fuel is consumed, or until the user remembers to attend to the candle.

This not only wastes the candle fuel, but can cause several obvious safety hazards.

Various attempts have been made to provide mechanisms to automatically extinguish candles that have been left unattended. Mechanical devices are known which are attached to the candle. These are commonly spring biased and act to move an arm or cover in place to extinguish the candle once the candle has burned to a selected level. An example of this type of candle is shown in U.S. Pat. No. 312,291. Numerous modifications to this type of device have been described and claimed, including, for example the device described in U.S. Pat. No. 6,572,365 in which a digital timer is utilized to close a candle housing after a selected period of time in order to extinguish the candle contained therein.

These devices, however, all require the candle to be connected to the mechanical device and/or require various timers to be set and maintained. This detracts from the aesthetic appearances of a candle, and can be limited in utility if, for example a larger candle is used than that for which the timer mechanism is designed.

Also, the predictability of the time until extinguishment can be variable depending on the nature of the device. For example, the nature of the solid fuel, the diameter of the candle, and even the composition of the wick material itself can affect the burn rate of a candle and can make estimation of the candle burn time difficult.

In GB 1405705, a candle is provided wherein a series of extinguishing agents is trapped within the solid fuel material, in the vicinity of the wick. In use, the candle will burn to the point where the extinguishing material, such as, for example, water, is released from the solid fuel material, in order to snuff out the candle. While this approach provides a candle with a controllable self-extinguishing feature that does not require the use of outside mechanical devices, its production can be difficult in order to provide a series of zones within the solid material that contain the extinguishing material.

It is noted that in a preferred option, the extinguishing material is housed within a series of ampoules which are attached to the wick prior to formation of the candle by pouring in the molten solid fuel material.

However, this approach requires that the ampoule remain intact and connected in the correct location adjacent to the wick. Also, care must be taken to avoid premature release of the extinguishing material onto the wick during production and/or use in order to avoid operational difficulties in using the candle.

As such, while this approach provides some advantages over the mechanical devices, it would be desirable to provide further improvements therein.

Accordingly, it would be advantageous to provide a self-extinguishing candle which avoided the use of external mechanical devices, and which avoided the use of ampoules of extinguishing materials which are to be located in the solid fuel material.

SUMMARY OF THE INVENTION

Accordingly, it is a principal advantage of the present invention to provide a self-extinguishing candle which avoids the use of external mechanical devices.

It is a further advantage of the present invention to provide a self-extinguishing candle which is free from having zones of extinguishing agent located within the solid fuel component of the candle.

It is a still further advantage of the present invention to provide a self-extinguishing candle which is easily and rapidly produced using conventional equipment and current candle-making techniques.

The advantages set out hereinabove, as well as other objects and goals inherent thereto, are at least partially or fully provided by the self-extinguishing candle of the present invention, as set out herein below.

Accordingly, in one aspect, the present invention provides a self-extinguishing candle comprising a wick, and a fuel material which surrounds said wick, characterized in that said candle has at least two separate combustion zones separated by a non-combustion zone wherein said candle is extinguished, and wherein said non-combustion zones is provided by a non-combustion zone within said wick, or by termination of said wick within said candle.

In a preferred embodiment, the wick includes the non-combustion zone. According, the present invention also provides a self-extinguishing candle, as hereinabove described, wherein said wick has at least two separate combustion zones along its length, and said combustion zones on said wick are separated by a non-combustion zone on said wick.

As a result, the candle can burn the wick in a first combustion zone, but on reaching the non-combustion zone, the candle is extinguished. However, the candle can be re-lit by removing the non-combustion zone of the wick, or by re-lighting the wick at a point beyond the non-combustion zone. Preferably, the wick has a plurality of combustion and non-combustion zones.

In a further aspect, the present invention also provides a candle wick of use in the practice of the present invention comprising an elongated combustible wick suitable for use in a candle, wherein said wick has two or more combustion zones, and one or more non-combustion zones located along its length.

DETAILED DESCRIPTION OF THE INVENTION

In the present application, the term “candle” refers primarily to common candles which have a wick surrounded by a solid fuel material. The present application is thus primarily directed to the use of these types of candles. However, the skilled artisan will be aware that non-solid materials might also be used, such as in the case of “gel” candles or the like, provided that consumption of the wick occurs as the candle burns. Accordingly, while the present application is described with particular reference to the traditional solid candle industry, the skilled artisan would be aware that the present application is equally applicable in other non-traditional applications.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this invention will now be described by way of example only in association with the accompanying drawings in which:

FIG. 1 is a cutaway perspective view of the side of a candle according to the present invention;

FIG. 2 is an enlarged view of the wick of the candle of FIG. 1;

FIG. 3 is an view of a first alternative wick according to the present invention;

FIG. 4 is a view of a second alternative wick according to the present invention;

FIG. 5 is a view of third alternative wick according to the present invention;

FIG. 6 is a view of fourth alternative wick according to the present invention; and

FIG. 7 is a view of fifth alternative wick according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The novel features which are believed to be characteristic of the present invention, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which a presently preferred embodiment of the invention will now be illustrated by way of example only. In the drawings, like reference numerals depict like elements.

It is expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

Referring to FIG. 1 a candle 10 is shown in a partial cutaway perspective side view comprising a solid fuel material 12 surrounding a central wick 14 which extends essentially completely through fuel material 12 and has an exposed end 16 which extends above the candle. At the top of candle 10 is an area of liquified fuel material 20 which forms continuously as solid fuel material 12 melts from the heat of flame 22 at the exposed end 16 of wick 14.

Dispersed at regular intervals along the length of wick 14 are a series of non-combustion zones 18 which will not support combustion. As such, as candle 10 burns and consumes solid fuel material 12, non-combustion zone 18 is slowly exposed. When a sufficient amount of non-combustion zone 18 is exposed, either through a physical or chemical method, the newly exposed non-combustible end 16 of wick 14 prevents candle 10 from burning past each non-combustion zone 18.

In the present application, the non-combustion zone is provided by a physical method wherein the weave density of the wick is increased at regular intervals to provide a wick with higher density zones 30 and lower density zones 32, as shown in FIG. 2. Higher density zones 30 are such that the wick capillary action is restricted so that the wick is prevented from conducting sufficient fuel to the end of the wick, as a result of the higher density zone.

Creation of the higher density zones 30, which forms non-combustion zone 18, can be accomplished by twisting the braided wick in the higher density zone to compress the wick materials closer together, and thus restrict the capillary movement of the liquified wax along the wick. In this higher density zone 30, the density of the wick material is thereby increased by tightening the weave of the wick, and thereby preventing transportation of the liquified fuel material to the exposed end 16, and thus to flame 22.

It is noted, however, that some liquified fuel may be able to pass through the higher density zone 30, but this amount of fuel will be restricted to the point where the candle flame 22 will ultimately be extinguished.

To re-light the candle, the higher density section of the wick can be cut off to expose the lower density wick material, or the higher density section can be partially unraveled to lower the density of the wick in that area. To assist the user, the higher and lower density portions can be identified by, for example, colour coding or the like so the user will know which part of the wick to remove before attempting to re-light the candle.

Candle 10, as shown is a cylindrical candle. However, any candle shape or size can be used in the practice of the present invention. This includes, candles having any desired geometric shapes, or candles which have been sculptured in appearance.

Candle 10 can also comprise any of a variety of known candle-making accessories. In this example, candle 10 has a wick tab 24, shown at the base of candle 10, which is used during candle production to hold the terminal end of the wick in place at the bottom of a container or mould when the container is being filled with liquified solid fuel. Wick tabs 24 can provide a short stem 26 through which the wick is inserted, which extends up into the candle. The stem and/or the tab can prevent the wax from reaching the wick at the bottom of the candle, and thus, assist in preventing a candle from burning completely down to the bottom of the wick, and thus burning down to the bottom of the candle.

Burning through the bottom of the candle is to be avoided in order to minimize the potential release of heated, liquified material through a hole created in the candle bottom, or to prevent a “flash-over” of a shallow collection of hot liquified solid material. As such, it is known to provide devices at the bottom of the wick for self-extinguishing the candle flame at the bottom of the candle.

Additionally, candle 10 includes a wick crimp 28, which are often used in combination with a wick tab 24, in order to further assist in preventing the candle from burning past a certain selected point. Wick crimps are usually made from metal or glass and are placed or crimped around the wick at the desired location. These devices can be located on any point on the wick, such as for example, if the candle were formed above a decorative sand base in the bottom of a container, and it was desired to prevent the candle from burning down to the level of the sand.

However, it is to be noted that wick crimps and/or wick tabs are only used to prevent the candle from burning past a particular point on the wick. As such, once a candle has reached the wick crimp and/or the wick tab, it is intended that the candle not be re-lit. As such, the prior art wick tabs and/or wick crimps are effectively located at the terminal end of the prior art wicks.

The candles of the present invention can be tapered or straight-sided, and can be free standing, or contained with housings such as glass, ceramic, plastic or metal housings. The candles might also be designed for specialized functions such as, for example, scented candles, birthday candles, wedding candles, pillar candles, votive candles, floating candles, or the like.

Any number of non-combustion zones can be provided on wick 14. The number can vary depending on the desired time between each self-extinguishing event, and will be dependent on the size of the candle, the candle solid fuel composition, the wick size, the wick material and composition, and the like. However, the skilled artisan would be able to determine the burn rate of a particular candle, and then determine the number of non-combustion zones to be provided in order to provide a candle that would self-extinguish at a desired rate. For example, if a candle were to normally burn for a total of 8 hours, three non-combustion zones spaced essentially equally from the top of the candle to the top of crimp 28, would provide a candle with four combustion zones, as shown in FIGS. 1 and 2, which would self-extinguish itself on a 2 hour interval.

It is noted that crimp 28, in combination with tab stem 26 would provide the final self-extinguishing event.

While the number of combustion zones can vary depending on the design parameters of the candle, preferably, the number of combustion zones in a candle, and also preferably on a single wick would be at least 2, and more preferably, at least 3. Even more preferably, the number of combustion zones in a candle, or on a single wick, will be between 2 and 10, and more preferably between 3 and 6.

The candles of the present invention can be made from any suitable fuel material including traditional solid fuel materials such as petroleum based waxes including, for example, paraffin waxes. Also, the solid fuel material can be made from animal-based fats such as tallow and the like, or made from traditional materials such as beeswax, soy wax, or any other suitable waxes. Further, the candles might be made from hydrogenated vegetable-based materials. Additionally, the fuel material 12 can be a combination of these materials.

The candles might also be made from non-traditional materials such as gel candles, which have a semi-solid material which is contained within a solid body such as a glass housing.

In a candle, the wick works by capillary action. Cotton fibers, or alternatively paper or some other types of fibres, are spun into threads, which are bundled and braided together. The spaces between the fibers, the threads, and braids act as capillaries, which cause liquids to be drawn into them. This capillary action causes the melted and liquified solid fuel in the vicinity of the flame to be drawn up through the wick where it is heated to a point where it vapourizes and is burnt in the candle flame.

Candle wicks, or wicking, is available in several types or styles, including flat or circular wicking. Different sized wicks cause different sized flames simply because of the number of threads in the bundles. Each thread is considered a plait or ply, and a given number of ply are bundled together. For example, a 36 ply wick could contain 3 bundles of 12 ply material. A 36 ply wick would typically draw more wax than a 30 ply wick can, which would result in the 36 ply wick providing a larger flame. In turn, the larger flame produces a slightly larger melt pool. However, design and selection of a proper size and type of wicking is a skill known to those skilled in the art.

The wick can also contain a solid core material, such as zinc or lead, which is provided to give the wick some rigidity, particularly in situations where a soft solid fuel is used, and/or when a relatively large amount of liquified fuel is encountered.

Other methods for providing the non-combustion zone on the wick can be provided, and some of these are exemplified in FIGS. 3 to 5.

In FIG. 3, wick 34 has a tab 24, with stem 26, and crimp 28, and has three non-combustion zones provided by metal clips 36 which are crimped around sections of wick 34 so as to essentially prevent the liquified solid material from passing along wick 34.

Metal clips 36 could be replaced by ceramic or glass clips, or by plastic clips (provided the plastic clips were not flammable).

After the candle has be extinguished, the exposed metal clip can be removed, and the candle re-lit.

In FIG. 4, wick 48 is shown having 4 combustion zones 47 which are physically separated from one another, but are held together by a thin fibre 45 which runs through each combustion zone 47 of wick 48. In use, the first combustion zone 47 would be ignited and would burn to the end. Fibre 45 is either non-flammable, or more preferably is merely incapable of providing sufficient capillary action for transportation of liquified fuel to the candle flame. As such, the candle with self-extinguish.

The distance between two combustion zones 47 of wick 48 are selected so that the wick will extinguish without igniting the next lower combustion zone 47. The user can then remove sufficient fuel to expose the next combustion zone 47.

However, as the first combustion zone is extinguished, it will commonly create an indented section of fuel in the vicinity of the wick. In a preferred feature, the next combustion zone 47 of wick 48 will protrude into this indentation.

As such, while the exact distance between combustion zones 47 will vary depending on candle design features, the distance is preferably less than 2 cm, and more preferably less than 1 cm.

In FIG. 5, wick 44 has three non-combustion zones 46 which have been created using a chemical means. In this embodiment, a bromine containing flame retardant material, that has been applied at the non-combusiton zones 46 in order to provide a flame retardant that is released once the flame reaches zone 46. Any suitable flame retardant can be used provided that sufficient material is provided to cause the flame to be extinguished. The flame retardant could be any of a number of different types of flame retardants, including the following.

Halogenated flame retardants, including compounds that contain, and release on combustion, fluorine, chlorine, or, in particular, bromine atoms. Different bromine containing flame retardants are known in the art, that have bromine atoms bound into different organic molecules. These materials offer different properties, in terms of how the bromine is bound into the flame retardant molecule (aliphatically, aromatically), and of how the flame retardant molecule interacts with the different materials. Different specific brominated compounds can thus be added to or chemically bound into these different materials without deteriorating their properties (flexibility, durability, colour and the like).

Additives such as antimony trioxide can be included to provide a synergistic effect with the halogentated flame retardants.

Phosphorus flame retardants might also be used, which act by generation of phosphoric acid, and thus inhibit the pyrolysis process. These can include, for example, elemental red phosphorus (P), which is oxidised to phosphoric acid with heat, through to complex P-containing organic molecules offering specific performance properties.

Nitrogen based flame retardants that release nitrogen when burned, including melamine-based materials.

Also, intumescent coatings might be applied to the wick.

Further, a wide range of materials might be used including inorganic flame retardants such as aluminium trihydrate, magnesium hydroxide, boron compounds, zinc borate, or the like.

In FIG. 6, an alternative design is shown in cross-section having a candle 50 having two wicks 52. Each wick 52 is identical and has alternating combustion 54 and non-combustion 56 zones. However, the wicks are positioned in an off-set fashion so that essentially only one wick has a non-combustion zone exposed at any given time.

The user would light the wick having a combustion zone 54 showing, and candle 50 would burn until that wick reached non-combustion zone 56. At that point, the candle would be extinguished, and the user, would then remove the exposed, un-burnt, non-combustion zone 56 of the other wick, and then light its combustion zone 54. It would be preferred that the wicks be designed and located close enough to each other to provide a common pool of liquified solid material that would envelop reach each wick when only one wick was lit. However, the wicks must be located a sufficient distance from each other so as to not allow the flame from one wick to be passed to the other when the combustion zone 54 of the second wick is exposed.

Using this principle, candles with additional wicks, such as candles with three or four wicks, might be manufactured.

In FIG. 7, a further embodiment of a candle 60 is shown wherein a series of small candle precursors 62 are prepared each of which has a fuel section 64 and a wick section 66. In production, preformed candle precursors 62 are stacked one on top of another, and fitted within a container, and liquified fuel 68 is poured in to the container where it solidifies to form candle 60. In a preferred embodiment, fuel 68 is the same as fuel 64 so that it blends with fuel 64. However, it must not be heated to a sufficient temperature to cause candle precursors 62 to melt to a sufficient point that wicks 66 are allowed to appreciably move.

In operation, each wick 66 will burn to the end of the wick so that their combustion is terminated, and candle 60 will be extinguish. The user can then re-light candle 60 using the next wick 66.

Additionally, combinations of the techniques described herein might be used. For example, a two wicks of the type described in FIG. 4 might be used in combination in a single candle in a fashion similar to that shown in FIG. 5. In this situation, the distance between wick combustion zones on a first wick would approximately equal the length of the combustion zone on the second wick. As such, the length of the non-combustible fibre would be approximately equal to the length of the adjacent combustion zone.

Further, this type of arrangement might be pre-produced by providing a “ladder”-shaped wick having a series of alternating combustion zones on different sides of the wick ladder, with non-combustible fibres forming the remainder of the wick ladder.

Thus, it is apparent that there has been provided, in accordance with the present invention, a self-extinguishing candle which fully satisfies the goals, objects, and advantages set forth hereinbefore. Therefore, having described specific embodiments of the present invention, it will be understood that alternatives, modifications and variations thereof may be suggested to those skilled in the art, and that it is intended that the present specification embrace all such alternatives, modifications and variations as fall within the scope of the appended claims.

Additionally, for clarity and unless otherwise stated, the word “comprise” and variations of the word such as “comprising” and “comprises”, when used in the description and claims of the present specification, is not intended to exclude other additives, components, integers or steps.

Moreover, the words “substantially” or “essentially”, when used with an adjective or adverb is intended to enhance the scope of the particular characteristic; e.g., substantially planar is intended to mean planar, nearly planar and/or exhibiting characteristics associated with a planar element.

Also, while this discussion has addressed prior art known to the inventor, it is not an admission that all art discussed is citable against the present application. 

1. A self-extinguishing candle comprising a wick, and a fuel material which surrounds said wick, characterized in that said candle has at least two separate combustion zones separated by a non-combustion zone wherein said candle is extinguished, and wherein said non-combustion zones is provided by a non-combustion zone within said wick, or by termination of said wick within said candle.
 2. A self-extinguishing candle as claimed in claim 1 wherein said wick has at least two separate combustion zones along its length, and said combustion zones on said wick are separated by a non-combustion zone on said wick.
 3. A self-extinguishing candle as claimed in claim 1 wherein the number of combustion zones on said wick is between 2 and
 10. 4. A self-extinguishing candle as claimed in claim 1 wherein said fuel material is a solid fuel selected from the group consisting of petroleum based waxes, animal-based fats, wax or hydrogenated vegetable-based materials.
 5. A self-extinguishing candle as claimed in claim 4 wherein said fuel material is a paraffin wax, tallow, beeswax or soy wax.
 6. A self-extinguishing candle as claimed in claim 1 wherein said non-combustion zone is provided by a physical method.
 7. A self-extinguishing candle as claimed in claim 6 wherein said combustion zone of said wick is provided by a relatively lower density zone, and said non-combustion zone of said wick is provided by a relatively higher density zone.
 8. A self-extinguishing candle as claimed in claim 7 wherein said wick is fabricated from a braided material, and said relatively higher density zone of said wick is provided by twisting said braided material to compress the braided material and thus increase the density of said wick.
 9. A self-extinguishing candle as claimed in claim 6 wherein said non-combustion zone is provided by one or more clips which are crimped around sections of said wick.
 10. A self-extinguishing candle as claimed in claim 9 wherein said clips are made of metal, ceramic, glass or non-flammable plastic.
 11. A self-extinguishing candle as claimed in claim 6 wherein said non-combustion zone is provided by a wick having a series of combustion zones, and wherein said combustion zones are separated by a non-combustion zone comprising a thin fibre which is non-combustible, or which has insufficient capillary action to support combustion.
 12. A self-extinguishing candle as claimed in claim 1 wherein said non-combustion zone is provided by a chemical means.
 13. A self-extinguishing candle as claimed in claim 12 wherein said non-combustion zone is provided by a flame retardant material which has been applied to said wick in said non-combustion zone.
 14. A self-extinguishing candle as claimed in claim 13 wherein said flame retardant material is a halogenated flame retardant, a phosphorus-based flame retardant, a nitrogen based flame retardant, or a inorganic flame retardant.
 15. A self-extinguishing candle as claimed in claim 1 wherein said candle comprises two or more wicks which wicks have a plurality of combustion and non-combustion zones, and said wicks are positioned so that, in use, the non-combustion zone on a first wick is horizontally adjacent to the combustion zone of a second wick.
 16. A self-extinguishing candle as claimed in claim 1 wherein said wick is colour coded to visually identify said non-combustion zones.
 17. A self-extinguishing candle as claimed in claim 1 wherein said fuel is a gelled material.
 18. A candle wick having comprising an elongated wick suitable for use in a candle, wherein said wick has two or more combustion zones separated by one or more non-combustion zones located along its length. 